Best semi-permenant box hair dye?

Hi! I have very golden, coppery, yellow blonde hair and it has GOT TO GO. I want to dye my hair light brown, but I'm a college student and I refuse to spend a fortune at the salon so I'm using box dye. I'm not sure if I'm going to like the brown, so I want to use a semi permanent dye first. So, which is the best semi permanent dye? (I am using L'oreal Feria to dye my hair permanently) and is a semi permanent hair dye damaging at all? Is it worth it? Will it damage my hair or do anything to it in the long run? Thanks!